CD163

GWB-C1B36B

9332

EDHu-1

Purified IgG prepared by affinity chromatography on Protein A from tissue culture supernatant

Acute phase-regulated receptor involved in clearance and endocytosis of hemoglobin/haptoglobin complexes by macrophages and may thereby protect tissues from free hemoglobin-mediated oxidative damage. May play a role in the uptake and recycling of iron via endocytosis of hemoglobin/haptoglobin and subsequent breakdown of heme. Binds hemoglobin/haptoglobin complexes in a calcium-dependent and pH-dependent manner. Exhibits a higher affinity for complexes of hemoglobin and multimeric haptoglobin of HP*1F phenotype than for complexes of hemoglobin and dimeric haptoglobin of HP*1S phenotype. Induces a cascade of intracellular signals that involves tyrosine kinase-dependent calcium mobilization inositol triphosphate production and secretion of IL6 and CSF1. Isoform 3 exhibits the higher capacity for ligand endocytosis and the more pronounced surface expression when expressed in cells.

Interacts with CSNK2B.

Cell membrane; Single-pass type I membrane protein. Note=Isoform 1 and isoform 2 show a lower surface expression when expressed in cells.

Induced by anti-inflammatory mediators such as glucocorticoids IL6 and IL10; suppressed by proinflammatory mediators like lipopolysaccharide (LPS) Interferon gamma/IFNG and tumor necrosis factor alpha.

A soluble form (sCD163) is produced by proteolytic shedding which can be induced by lipopolysaccharide phorbol ester and Fc region of immunoglobulin gamma. This cleavage is dependent on protein kinase C and tyrosine kinases and can be blocked by protease inhibitors. The shedding is inhibited by the tissue inhibitor of metalloproteinase TIMP3 and thus problably induced by membrane-bound metalloproteinases ADAMs.

The soluble form (sCD163) in plasma is a novel parameter in diseases affecting macrophage function and monocyte/macrophage load in the body. The concentration of sCD163 is probably reflecting the number of macrophages of the \' alternative macrophage activation\' phenotype with a high CD163 expression playing a major role in dampening the inflammatory response and scavenging components of damaged cells. This has initiated a number of clinical studies for evaluation of sCD163 as a disease marker in inflammatory conditions e. g. infection autoimmune disease transplantation atherosclerosis and cancer.

Contains 9 SRCR domains. 1. Kristiansen. M. et al. (2001) Identification of the haemoglobin scavenger receptor. 2. Madsen. M. et al. (2004) Molecular characterization of the haptoglobin. hemoglobin receptor CD163. Ligand binding properties of the scavenger receptor cysteine-rich domain region 3. Kim. W. K. et al. (2006) CD163 identifies perivascular macrophages in normal and viral encephalitic brains and potential precursors to perivascular macrophages in blood.